Pex Manifold ?

peteh2833 · January 05, 2009, 05:01:18 PM

I am ready to start the plumbing in my 1.5 story 20x30. There will be a kitchen sink, a bathroom sink, toliet, shower/tub and a washer and dryer. I am definately using the Pex tubing. I was going to run 1/2 through out the house. Should I use a manifold for the hot an a manifold for the cold side? Thanks Pete

ScottA · January 05, 2009, 05:07:28 PM

I would and put shut off valves on each line at the manifold.

January 05, 2009, 05:09:52 PM

I used a manifold for the hot and cold side and put shut off's at each location too.

peteh2833 · January 05, 2009, 06:03:57 PM

Thanks for the info. ScottA, should I run 1/2 or 3/4 into the manifolds??

MountainDon · January 05, 2009, 06:10:31 PM

3/4 into the manifold for certain. I've seen some with 1" inlet. You can buy them with valves at each branch line built in.

January 05, 2009, 07:39:36 PM

Yep. What Don said.

phalynx · January 05, 2009, 08:18:58 PM

Here is what my distribution looks like. 3/4 inlet, split to the water heater and then to the manifolds. 1/2" distributed to all the fixtures.

curlewdave · January 06, 2009, 09:08:45 AM

What type of fittings did you use in the system? There are several types, and I've been trying to figure out which type is "best". I've got to replumb an older farmhouse this summer using PEX, and looking thru the PPFA Design Guide I notice a variety of fitting types.

MountainDon · January 06, 2009, 10:05:40 AM

There are three systems; Wirsbo/Uponor is generally acknowledged as the best. Then there is one that uses annealed copper bands to crimp; those are the ones where there are a different tool or a different sized tool head for each size. Then there is the system that uses stainless steel clamping bands; only one tool needed for all sizes, but the S/S clamps cost more than the annealed copper crimps rings.

Wirsbo tools cost more but you still save oodles of money compared to having the entire job farmed out to a hired plumber. Wirsbo/Uponor fittings are not interchangeable with the others.

January 06, 2009, 10:20:36 AM

Thanks for the reply. In some homes built nearby I've snooped enough to see copper crimp rings used in one, stainless rings used in another, and metal compression sleeves used in a third. I haven't caught up with a plumber to find out the relative merits of each type.

perhaps cost? I just want to put in a system that will be put in ONCE. (read- I hate repair work). So a few extra bucks on fittings is a small price. The manifold system surely looks like the way to go.--Dave

phalynx · January 06, 2009, 10:37:06 AM

I used Wirsbo/Uponor. I can honestly say, I don't think there will be a failure of the connection. In about 5 seconds, you couldn't pull it apart. It takes about 30 seconds for the hose to shrink fully. You get an aweful lot of compression in the full 30 seconds. It takes me a better part of 5 minutes to shred one apart if I mess up. They are truly strong.

MountainDon · January 06, 2009, 10:38:11 AM

Wirsbo/Uponor uses an expander tool to stretch the PEX tubing. As phalynx stated, the fitting is inserted and positioned before the tubing shrinks back to size; about 30 seconds. Then a ring is slid over the joint to secure it. The plumber that did my home re-pipe used this.

I have one of the tools for the S/S clamp rings. I chose it because the Wirsbo tool was hundreds of dollars more and I only had a small project. One other reason was that the tool does not fit around the band, making it a little easier to use in cramped quarters. Plus one tool does all sizes.

I've also used the tools for the annealed copper rings. They work well, but I still prefer the S/S over it, for working in crowded quarters mainly.

A fourth system us the specially slip on fittings like the Sharkbite brand name. They are super simple to use and require no special tools. However the fittings cost about six to ten times as much as the standard PEX. Great for a small job or a repair but I'd never use them for an entire house. They do work well, though. I have used a couple on a 1/2" copper line.

glenn kangiser · January 06, 2009, 11:35:59 AM

Wirsbo/Uponor requires that you take a short certification course and that you be a contractor to get their product, but I have heard of non-contractors being able to get the supply co. to certify them in some cases. They do not want anyone to improperly install their system.

I prefer the Uponor system as I feel it has less chance of a leak than the crimps. My opinion.

MountainDon · January 06, 2009, 11:44:16 AM

Quote from: glenn kangiser on January 06, 2009, 11:35:59 AM
Wirsbo/Uponor requires that you take a short certification course ...

There sources now that anyone can use for this style of connection. Not the genuine product but completely interchangeable.

http://www.pexsupply.com has all three.

January 06, 2009, 11:48:19 AM

I was thinking there was something but couldn't remember where. Thanks for the link, Don.

MountainDon · January 06, 2009, 11:54:32 AM

I bought fittings and clamps from them, but I bought my tool on eBay. Fittings were about half the price at Lowe's; I saved a lot even with the shipping costs.

phalynx · January 06, 2009, 12:08:09 PM

I bought my tool from them with no problems at all.

peteh2833 · January 06, 2009, 02:47:44 PM

Any suggestions on how to install it so that I can drain it out easily? I will be using it in the winter and need an easy way to drain it out so the manifolds and the system doesn't freeze. Pete

phalynx · January 06, 2009, 03:31:36 PM

You just need a air fitting. Hook it up to your air compressor, turn off the water, open the valves.

The good thing about PEX is it doesn't break when it freezes. You can release the pressure, and let it freeze. It just expands.

curlewdave · January 06, 2009, 04:37:41 PM

I'm thinking of using compression fittings, but where can I find a compression tool? I found a site on the internet that demonstrated its use, but haven't found the tool. It has 2 ends, one expands the tubing, and the other end then is used to pull the compression fitting tight over the end. I've used the crimping tool on some Habitat for Humanity homes, and it worked fine, but am interested in the compression fittings. Why?? Well, my wife asks me that quite often...I search for an answer.....

January 06, 2009, 04:48:11 PM

www.pexsupply.com has them. That's where I got mine.

peteh2833 · January 06, 2009, 04:48:29 PM

Thanks. That is what I planned on doing. Any suggestions as to where I should locate the air fitting?

n74tg · January 06, 2009, 05:16:23 PM

It seems to me there is no real advantage to using a PEX manifold. It just increases the amount of PEX pipe needed, requires additional stuff (the manifold), and makes it more difficult to get hot water to any faucet (because of that extra length pipe)(unless you insulate all your hot water lines).

Granted it does give you the ability to turn off any "circuit" easily, but we didn't have that ability with copper piping, so do we really need it with plastic piping?

What am I missing here?

peteh2833 · January 06, 2009, 05:44:06 PM

I hear what your saying. I was thinking the same thing. The benefit of the manifold that I see is that there are no fittings inside the wall that could fail or leak. I was going to use the manifold and be able to access it with a door. Pete

MountainDon · January 06, 2009, 06:12:43 PM

Quote from: peteh2833 on January 06, 2009, 04:48:29 PM
Thanks. That is what I planned on doing. Any suggestions as to where I should locate the air fitting?

It should be located as close as possible to the place where the piping enters the house. Everything down strean can then then be blown out.

Regarding PEX being able to withstand freezing; true. However, that does not necessarily apply to fittings.